I am going to rewire my MC 8 headlights which are now wired in the series system and was upgraded by Greyhound in 1981. I have changed relays, diodes, grounds, switches and it has given me nothing but grief. I am going to wire them up like a 12v car. I sincerely appreciate the fact that the stock system worked great for years but please don't try to talk me out of this. I have installed a Vanner Equalizer .

Here are my questions:

What wire size should I run from the equalizer to the drivers junction box where I will build a 12v bus bar. The equalizer is mounted in the battery compartment.

What wire size from the 12v to the new 12v bus bar which will be in the drivers junction box?

What wire size for the low beams and high beams.

Can I run all of the high beams 4 filaments burning, off of one relay ?

I just did this. I ran 8 gauge wire from the house battries to the panel beside the drivers seat. Put in a circuit breaker, a three way switch with center being off, up being high beams, down being low beams. I took the high beam indicator and wired it to the high beam side and used the one for low lav to tell me when the head lights are on. Works great and I like the fact I don't have to try to find the floor mounted dimmer switch with my big foot. By the way mine is a 1973 MCI 7ED

I would run 2 separate relays, one for high, and one for low beam. That way you can use high and low beam at the same time if you need or want to. With 2 relays if you loose one, you still have one set of lights to get you where you can repair it.Jim

When I re-did the headlights on our MC-8, the first thing I did was modify the high beam cans to aqccept high-low beam bulbs. I then installed 4 hi-lom beambulbs. The high nd low beams are 2 completelty differnt circuits. We now have 4 low beam as well as 4 high beam lights. On low beam, the light is directed closer to the ground and we have never had anyone flash their lights at us when using our low beams. This also gives us the redundancy, if we burn out a low beam, we still have at least one on each side. Jack